But only the opinion of the recipient counts. So says a blog post on All Spammed Up.

I’m sorry, but you don’t get to decide that. And by “you” I mean businesses. Businesses and their marketing departments who look at email as a fast, convenient way to reach a lot of people with their very important messages.
Now for the purposes of this discussion I’ll make some definitions clear. I’m not talking about the kind of spam that botnets send out to try and trick people into buying fake pharmaceutical goods or a counterfeit watch.
I’m talking about UCE – unsolicited commercial email. The kind of email you get when a company decides to add you to their marketing newsletter without you ever requesting it, and without a double opt-in process. The law might say this isn’t spam, but every customer I talk to says it is. And guess who gets to decide that? The customer does.

There is more than a grain of truth in there. Recipients have more influence in the spam / not-spam decision than senders do. Even if a sender is complying with CAN SPAM, recipients may still call the mail spam. And if the recipients tell their ISP, their spam filtering company or their mail client that the mail is spam then the sender may lose access to that recipient. If enough recipients tell an ISP mail is spam, then the sender loses access to all recipients at that ISP.
This shift in influence to the receivers means that senders need to remember that keeping recipients happy is a critical part of any successful email marketing program. Senders that annoy their recipients lose access to those recipients and their wallets.

links • Spam